​ Abstract: The GePb-based device is emerging as a significant competitor to traditional Group III-V photonic devices. Direct bandgap III-V materials employed in optoelectronic devices, including GaAs, are expensive and pose safety risks. However, a notable enhancement is achieved by alloying lead with Germanium (Ge) or silicon (Si) or their respective alloys (Ge _1-x Si _x ). The SiGePb-based Barrier-Well-Barrier heterostructure, operating in the mid- to far-infrared range, has been analyzed both analytically and through simulations conducted using the Silvaco TCAD simulator. Adding lead (Pb) to Group IV heterostructures (Ge _1-x Si _x ) has shown that it can change the energy levels and create quantum confinement effects. The band profile and band offsets are analysed and compared with theoretical values, concluding that the structure is a compressively strained type II model. The calculated crossover concentration of Pb for the transition from an indirect to a direct bandgap is 0.3 %. The absorption coefficient and optical gain are determined using the carrier injection method, with the peak gain compared to the corresponding experimental data.

Keywords: Energy-bands, Band-offsets, Heterostructure, Optical gain, TYPE-II.

__________________________________________________________________________________________